Prosthetic urethral valves of the prior art for incontinent patients involve numerous disadvantages. Most urethral valves of the prior art involve an inflatable cuff around the outside of the urethra, or a catheter that extends beyond the distal end of the urethra. The former type of urethral valve requires surgery for installation, and the latter type is non-cosmetic and invites infection. Also, most of the previously proposed urethral valve devices must be operated externally and depend on manual intervention.
Therefore, there is a definite need for a non-surgically installed prosthetic urethral valve which has functional sensitivity to the natural physiological sustained internal bladder pressure produced voluntarily by the patient, rather than by external manual control.
A preliminary search of the prior U.S. patents relating to this art revealed the following U.S. prior patents of interest all of which suffer the aforementioned defects:
Kulick, 2,638,093; PA1 Beliveau, 3,372,695; PA1 Rosen et al, 3,903,894; PA1 Reinicke, 4,167,952; PA1 Ward et al, 4,209,010; PA1 Burton, 4,222,377; PA1 Helms et al, 4,256,903; PA1 Trick, 4,386,601.